Add source of documentation for this driver.
Thanks to Warren Block for the suggestions for readability.
Note that strict_rx_mtu in inverted in stable/7/8/9 and is
named loose_rx_mtu. Ensure that this is converted over when MFC'd
hw.bce.rx_ticks
hw.bce.rx_ticks_int
hw.bce.rx_quick_cons_trip
hw.bce.rx_quick_cons_trip_int
hw.bce.tx_ticks
hw.bce.tx_ticks_int
hw.bce.tx_quick_cons_trip
hw.bce.tx_quick_cons_trip_int
hw.bce.strict_rx_mtu
hw.bce.hdr_split
hw.bce.tx_pages
hw.bce.rx_pages
hw.bce.tso_enable
hw.bce.verbose
Reviewed by: Warren Block <wblock@wonkity.com>
MFC after: 3 days